# Calculate the Mean of each Column of a Matrix or Array in R Programming – colMeans() Function

** colMeans()** function in R Language is used to compute the mean of each column of a matrix or array.

Syntax:colMeans(x, dims = 1)

Parameters:x:array of two or more dimensions, containing numeric, complex, integer or logical values, or a numeric data framedims:integer value, which dimensions are regarded as ‘columns’ to sum over. It is over dimensions 1:dims.

**Example 1:**

`# R program to illustrate` `# colMeans function` ` ` `# Initializing a matrix with` `# 3 rows and 3 columns` `x <` `-` `matrix(rep(` `1` `:` `9` `), ` `3` `, ` `3` `)` ` ` `# Getting matrix representation` `x` ` ` `# Calling the colMeans() function` `colMeans(x)` |

**Output:**

[, 1] [, 2] [, 3] [1, ] 1 4 7 [2, ] 2 5 8 [3, ] 3 6 9 [1] 2 5 8

**Example 2:**

`# R program to illustrate` `# colMeans function` ` ` `# Initializing a 3D array` `x <` `-` `array(` `1` `:` `12` `, c(` `2` `, ` `3` `, ` `3` `))` ` ` `# Getting the array representation` `x` ` ` `# Calling the colMeans() function` ` ` `# for dims = 1, x[, 1, 1], x[, 2, 1], x[, 3, 1],` `# x[, 1, 2] ... are columns` `colMeans(x, dims ` `=` `1` `)` ` ` `# for dims = 2, x[,,1], x[,,2], x[,,3]` `# are columns` `colMeans(x, dims ` `=` `2` `)` |

**Output:**

,, 1 [, 1] [, 2] [, 3] [1, ] 1 3 5 [2, ] 2 4 6,, 2 [, 1] [, 2] [, 3] [1, ] 7 9 11 [2, ] 8 10 12,, 3 [, 1] [, 2] [, 3] [1, ] 1 3 5 [2, ] 2 4 6 [, 1] [, 2] [, 3] [1, ] 1.5 7.5 1.5 [2, ] 3.5 9.5 3.5 [3, ] 5.5 11.5 5.5 [1] 3.5 9.5 3.5